Carburetor



June 24, 1930. J. R. FRANCIS 1,766,708

CARBURETOR Filed June 15, 1921 gwumfloz 1 72, 7 Vzmcz'a.

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fiTATES JACOB RICHARD FRANCIS, F FLINT, MICHIGAN CARBUEETOR Application filed June 15,

This invention relates to certain new and useful improvements in carburetors and more particularly to means for controlling the movement of the air or suction controlled valve, the object being to provide a combination air and gasoline dash pot connected to the valve in such a manner that the valve will be prevented from clattering when in use.

inother and further object of the invention is to provide a dash pot control for the pivoted valve which operates as an air dash until the gasoline accumulates therein, when it operates as a fluid dash pot. The well, be-

ing in communication with the bottom of the mixing chamber, receives the gasoline or fluid from the drift or bacletlow when the motor is in operation or on the choking or the flooding of the carburetor, whereby the sur- "Jlus of gasoline is collected so as to prevent the same from dripping out of the carburetor.

()ther and further objects and advantages of the invention will be hereinafter set forth and the novel features thereof defined in the appended claims.

In the drawings,

Figure 1 is a side elevation of a carburetor partly in sect-ion showing the application of my improved construction of dash pot for retarding the closing H1OV6l1lllb of the valve;

and

Figure 2 is a section taken on line 22 of Figure 1.

In Figure 1 of the drawing T have shown a v side elevation of a type of carburetor as disclosed in the patent issued to B. N. Pierce, January 25, 1921, No. 1,366,831, partly in section, in which 1 indicates a shell provided with a mixing chamber 2 having a lateral air inlet 3. The bottom of the mixing chamber is closed by insert 4 having an extension formin a support for the float chamher 5. The insert 1 is provided with a body portion 6 having a vertical bore through which the low speed nozzle 7 extends which is fed from a fuel passage 8, said passage having extending therefrom a high speed nozzle 9 terminating adjacent the wall of the mixing chamber above the air inlet 3. The insert 4 is provided with a circular boss 9 1921. Serial No. 477,769.

air or suction controlled valve 10 which is held normally in contact with the wall of the mixing chamber over the high speed nozzle 9, the above eescription being given so that ie operation of my improved construction or dash pot can be readily understood when appl'ed to this type of carburetor.

The insert at is provided with an internally threaded boss 11 in which is screwed the threaded upper end of a cylinder 12, the uper e Lge engaging a gasket 13 so as to form tight oint and prevent the leakage of casoline or other fuel used for forming the explosive charge. A vertical opening 1 1 is formed in the insert extending from the top of the internally threaded boss through the bottom to one side of an enlarged portion 15 formed in the top of the insert within the body of the carburetor.

The enlarged portion 15 to one side of which extends the piston rod 17 forms a dam across the bottom of the carburetor so that any drippage or accumulation of gasoline in the bottom of the carburetor will be prevented from running out the air inlet thereof and will naturally run down through the opening into the cylinder of the dash pot.

While I have shown this construction of carburetor with an insert and a dam formed in this particular manner, I am of course aware that a dam can be formed in various other ways for accomplishing this result and therefore I do not wish to limit myself to any details of construction.

Within the cylinder 12 is a piston 16 of a diameter slightly less than the internal diameter of the cylinder 12 and to which is connected piston rod 17 extending up through the vertical bore 14- and has its upper end pivotally connected at 18 to an arm 19 carried by the air or suction controlled valve 10, whereby the movement of the valve will be controlled by the piston.

lVhile I have shown the piston 16 formed of a less diameter than the internal diameter of the cylinder, it is, of course, understood that a piston of the same diameter of the cylinder can be employed and an opening formed in the piston to form av by-pass for the fluid as the piston works up and down, and therefore I do not wish to limit myself to the detailed construction of cylinder and piston as I am aware that various changes can be made without departing from the spirit of my invention.

As the valve 10 over the high speed nozzle swings on its pivot by the suction of the engine, the piston 16 works up and down within the cylinder so as to retard the opening and closing mo\ement of the valve and the main object of my invention is to provide a dash pot control wliftch will prevent the free end of the valve from hammering on the inner wall of the mixing chamber in closin"; and in some instances. it may be found dvisable to allow the valve to open quickly f r picking up and to provide a construction which will prevent the valve from closing quickl as I have found in practice that by connecting up the dash not with a valve of is construction, the difficulties now existg with the use of a spring for preventing the o ening of the valve is overcome and the valve swings on its pivot slowly so as to revent the same from being forced quickly to nga rement with the wall of the mixing '"nb r by the reduced suction through the a uretor.

When a carburetor as herein shown is connected to an internal combustion engine, the dash pot acts as an air dash until the cylinder becomes filled with the fluid used for forming the explosive mixture, which fluid by he drift or back-flow accumulates in the bottom of the carburetor and passes hrough the vertical bore into the cylinder. This construction also provides means for taking care of any excess gasoline caused by the choking of the motor or by the flooding of the bowl as any excess of gasoline which accumulates in the bottom of the mixing chamber passes into the cylinder of the dash pot.

It will also be seen that this construction provides a dash pot control for the suction controlled valve which utilizes the waste gasoline and is in no way connected with the supply or bowl of the carburetor and prevents the fluttering of the air valve.

From the foregoing description it will be seen that I have provided a carburetor having a suction controlled air valve connected to a dash pot so as to prevent the fluttering of the air valve thereby eliminating the noise in this type of carburetor.

I am aware that various changes can be made without departing from the spirit of my invention as my invention consists broadly in providing a combination air and gasoline dash pot for a carburetor employing a suction controlled air valve which operates as an air valve until the cylinder or well accumulates the desired amount of fluid used for forming the explosive charge.

What I claim is 1. The combination with a carburetor having a mixing chamber provided at its bottom with a removable insert, of a pivoted suction controlled valve carried by said insert, a cylinder carried by said insert in communication with said mixing chamber provided with a piston and a connection between said suction controlled valve and said piston for retarding the swinging movement of said valve.

2. A carburetor havin I a mixing chamber provided with a removable insert at its bottom and provided with a body portion having a vertical bore, a low speed nozzle extending into said bore, a high speed nozzle extendlnginto saidmixing chamberfrom said insert, a pivoted air valve carried by said body portion over said high speed nozzle, a cylinder carried by said insert in communication with the mixing chamber, an arm can ried by said air valve and a piston rod carried by said piston connected to said arm.

In testimony whereof I hereunto afiix my signature.

JACOB RICHARD FRANCIS. 

